* {
  padding: 0;
  margin: 0;
}
body {
  width: 100vw;
  height: 100vh;
  display: grid;
  justify-items: center;
  align-content: center;
}

.app {
  display: grid;
  grid-template-columns: repeat(10, 50px);
  grid-auto-rows: 50px;
  border: 2px solid #33e;
  position: relative;
  overflow: hidden;
}
.app div {
  border: 1px solid #f1f1f1;
  box-sizing: border-box;
}
.app .snake {
  position: absolute;
  width: 50px;
  height: 50px;
}
